Copy 1 | 



ELESTIAL INDICATOR. 




tffefUFACTURED BY 



THE BRYANT CELESTIAL INDICATOR CO., 

HARTFORD, CONN. 



Price lO Cents. 



A. 



SYNOPSIS 



ELEMENTS OF ASTRONOMY, 



AND A DESCRIPTION OF THE 



CELESTIAL IKDICATOK; 



WRITTEN TO ACCOMPANY THE APPARATUS, 

BY THE INVENTOR. 

' <l(/[ 

/ 

HARTFOKD : 
PRESS OF CASE, LOCKWOOD AND BRAXNAHD. 

1871. 



a 



b 



*1 



CELESTIAL INDICATOR 



Astronomy is the science which teaches the knowledge 
of the stars ; a study that has " at once the beauty of 
poetry, and the exactness of Geometry." We look in all 
directions, on a clear evening, and we see a multitude of 
stars ; were we to remain out all night, we should continue 
to see them coming up in the east, and going down in the 
west, until the dawn of morning obscured them from our 
sight. The sun rises ; it is but a star, like those seen in 
the night ; and were it as far away from us as the other 
stars, we should continue to see stars all the time under a 
clear sky ; but, being comparatively near us, it looks large 
and gives us a flood of light {hat makes our day. Its 
distance is but 92,000,000 miles, and its light but eight 
minutes in reaching us, while the light from the next near- 
est fixed star, « Centauri, is more than three years in 
reaching us ; and the light from some of the remoter fixed 
stars, that are seen with telescopes, would require a hund- 
red thousand years to travel to us ; yet their light is here, 
and the Beyond — a boundless space — yet filled with stars. 



4 THE CELESTIAL INDICATOR. 

We live among the stars and amidst star-systems ; yet 
we see less than 10,000, with our unaided vision; with the 
telescope, more than twenty millions. 

But now we will confine our description to one star, and 
its planets moving eastward around it. To us it is a sun, 
yet it is one of the fixed stars belonging to the great group 
of the Milky Way, standing alone in space, and shining by 
its own light, billions of miles from any other fixed star ; 
having near to it eight planets that shine not by their own 
light, but by the light they reflect from the sun — some 
of these also having satellites or moons. This group, the 
cun, its planets and their moons, is called our solar system. 
* The Celestial Indicator, which I now present to you, is 
constructed to illustrate the various phenomena of this 
system. 

As I pass along, I will describe these phenomena, and the 
Indicator ; using the instrument to illustrate and make 
clear to you those points that would be difficult for you- to 
understand without its aid. 

There is in the great star-system a star called Polaris, 
or Pole-star, otherwise called the north star, probably 
known to most people. You should all know its place in 
the heavens, for in the commencement of the study of 
astronomy, this is the important standpoint; from this 
direction we can look toward and easily comprehend our 
solar system. It is due north, standing quite alone, and 
elevated as much above the horizon in degrees, as our lati- 
tude is north of the equator. 

Thus, in Hartford we are in 41° 36' north latitude ; con- 
sequently the star is above our northern horizon 41° 36'. 

I will now T describe to you a part of the Indicator. 



THE CELESTIAL INDICATOR. 5 

I place it on the table with its polar map facing the 
north, for the reason that it has a polar star located in re- 
lation to its other parts, the same as the polar star in the 
Heavens stands in relation to the solar system ; and I 
desire to have yon comprehend the whole phenomenon that 
I am abont to explain. 

I now bring the revolving meridian over the top of the 
apparatus, and as yon look at it, it is intended to represent 
the Sphere of the Heavens. I want yon to imagine it so 
expanded as to reach the stars. 

On the center of the northern part of this Indicator is 
the location of the north star. In the center of the ap- 
paratus is a large brass ball, that represents the sun, and the 
smaller balls surrounding it represent the planets. Their 
positions (except in size and distances) stand in relation 
to its north star the same as the position of the solar- 
system stands in relation to the north star in the Heavens. 

Please fix this well in your minds. 

First, I will point out the equator of the Indicator. It 
is a narrow strip of brass passing entirely around it east 
and west. A line from its north star through the center 
of this apparatus would represent its axis, and this equa- 
tor and the axis represent the celestial equator and the 
axis of the heavens, as they are related, in position, to the 
north star of the Heavens. 

This equatorial rim of brass is marked into 360 parts 
called degrees (°) ; just as the celestial equator is divided 
into the same number of degrees. 

On the Indicator is another rim of brass, beginning at its 
north star, and passing horizontally around its central part, 
to its starting point ; so is there an imaginary line passing 
entirely around the sphere of the celestial Heavens. The 



6 THE CELESTIAL INDICATOR. 

brass rim and this imaginary line around the Heavens are 
called the first meridian or equinoctial colure, (a great cir- 
cle passing through the equinoxes.) At the vernal equi- 
nox, where the first meridian intersects the equator or equi- 
noctial, I begin to place the degree-divisions before spoken 
of, and extend them eastward around the Indicator, ending 
with 360° at the point I started from, so that the first 
meridian again intersects the equator at the autumnal 
equinox half way around, or 180°. Just so is the imagin- 
ary first meridian placed, in relation to the celestial equator 
of the Heavens, and in like manner are the imaginary de- 
grees placed on the great circle of the equator or equinoc- 
tial of the Heavens. We begin to count the longitude of 
the Heavens at the west side of the sphere on the first me- 
ridian, and as we go east, we call it right ascension. 

Attached to the poles of the axis of the heavens on the 
Indicator, is a semi-circular rim of brass, called a revolv- 
ing meridian, one edge of which is divided into 180°, begin- 
ning to count at the north pole going southward, and meas- 
ures polar distance. The other edge is also divided into 
degrees, beginning at the middle and counting each way 
to 90°. 

To indicate north and south declination, move the revolv- 
ing meridian from 0°, the initial point of right ascension, 
along up the equator of the Heavens to 90° R. A. ; it will 
then represent the solstitial colure, or the great circle run- 
ning through the solstices. Follow the figures on it toward 
the north pole or polar star 30°, and you are at a point in 
the heavens called right ascension, (R. A.) 90°, and north 
declination 30°, (N. D.) In this way. you find any point 
of right ascension, and also of north or south declin- 
ation. This revolving meridian is also used to locate the 



THE CELESTIAL INDICATOR. 7 

hour-circle of 15° K. A., and thus we make the divisions 
and count on the great imaginary circles of the celestial 
sphere. 

The pupil should thoroughly understand this, and be 
able to apply it out of doors. To find the first meridian, 
step out of doors on a clear evening, say about the middle 
of November, and look at the north star, from which the 
first meridian of the heavens can be easily traced among 
the stars. Looking south of the pole-star about 31° you 
will see the bright star Caph ; farther south 62° the bright 
star Alpheratz ; then 15° south of Alpheratz the bright 
star Algenib. The two latter stars are on the east side of 

- o 

the great square of Pegasus, (a figure easily found and 
never forgotten.) The four stars pointed out are in a 
direct line, and it is along this line of stars that the first 
meridian lies. 

To find the equator of the Heavens, take two straight 
sticks, cross and nail them together at right angles, then 
nail them to the side of a firm perpendicular post, letting 
one of the sticks point directly to the north star, the other 
stick will of course (as they cross at an angle of 90°) point 
out the equator of the heavens. Now as the earth revolves 
on its axis eastward, the stick that does not point to the 
north star is always describing the great circle of the equa- 
tor of the Heavens, corresponding to the one on the Indi- 
cator, and any star on the line that the stick intersects will 
be on the celestial equator. 

Looking along its length from time to time on the clear 
evenings you will soon know the stars that girdle the 
Heavens along the equator. 

Looking again at the Indicator, you will observe a band 
of stars on a dark ground, 16° wide, encircling it and cross- 



8 THE CELESTIAL INDICATOR. 

ing its equator at an angle of about 23^°. This is called 
the zodiac, and embraces within its limits our solar system. 
It is divided into twelve parts of 30° each, on which are 
placed the following signs — Aries °rY Taurus bj Gemini e , 
Cancer 53>, Leo £1, Virgo W, Libra ^, Scorpio m, Sagit- 
tarius t, Capricornus VJ, Aquarius ££, Pisces X. It also 
has twelve constellations of stars, bearing the same names, 
but located 30° in advance of the signs ; — thus the con- 
stellation of Pisces is in the sign of Aries, and so on. The 
cause of this displacement will be told presently. Through 
the center of the zodiac is a line divided into degrees, and 
this line represents the Ecliptic, or pathway of the earth 
around the sun. You will see this line intersecting the 
Equator or Equinoctial at the 1° in Aries; and again at 
the 1° in Libra, or 180° P. A. These are the equinoc- 
tial points, and the equinoctial points are always where 
these two lines intersect. Suppose you could connect the 
opposite sides of the Ecliptic with something across, like a 
sheet of paper placed in that position on the indicator, you 
would call it the plane of the Ecliptic. The revolving 
meridian will give you the declination of the Ecliptic, so 
that you can find its position on the Indicator and apply 
it to its place in the Heavens at any time of the year, by 
having previously learned the position of the equator of 
the Heavens. 

The large brass ball on the center of the shaft is in- 
tended to represent the sun. It is located in the center of 
the zodiac, and is stationary, as for all practical purposes it 
may be regarded, only it revolves eastwardly on its axis 
once in about 27 days. Around it on the Indicator are 
placed eight smaller balls to represent the eight planets, all 
within the limits of the zodiac. In nature they all revolve 



THE CELESTIAL INDICATOR. d 

eastward in slightly elliptical orbits around the sun, having 
an axial motion eastward like the sun. Their orbital paths 
are nearly parallel *to each other, crossing the Ecliptic at 
small and varied angles, and the planets vary of course in 
the length of their time of revolution, as well as in their 
axial motion, as their size, density and distances vary. 

Those that are farthest off travel the slowest, and they 
gradually increase in speed, the nearer their orbits are to 
the sun. Mercury being the nearest to the sun is the 
swiftest in its motions. Its distance from the sun is 35,000,- 
000 miles; its periodic time, 88 days ; its diameter, about 
3,000 miles. 

The next is Yenus, whose distance is 66,000,000 miles; 
periodic time, 224 days ; diameter, 7,500 miles. These are 
called the inferior planets, because their orbits are within 
that of the earth. 

Next m order is the Earth, on which we live, whose dis- 
tance from the sun is about 92,000,000 miles ; its periodic 
time 365^ days; its diameter, about 8,000 miles. Of the 
superior planets (outside of the earth's orbit) the first is 
Mars, distant from the sun 139,000,000 miles; its ]3eriodic 
time being 686 days, and its diameter about 4,000 miles. 
The next in order are the asteroids, small planets ; a large 
number (112) have been discovered, sweeping in vast orbits 
around the sun in a region between Mars and Jupiter ; orbits 
somewhat more eccentric than those of the larger planets, 
and making greater angles with the Ecliptic. They are 
invisible except through the telescope. They are supposed 
to have once formed a large planet, which from some un- 
known cause was blown to atoms. A planet seems to be 
wanted in this region, in order to satisfy our conceptions 
of symmetry in the solar-system. 



10 THE CELESTIAL INDICATOR. 

Next to the Asteroids is Jupiter, whose distance from the 
sun is 475,000,000 miles, its periodic time 4,332 days, and 
its diameter 88,000 miles. 

Next to Jupiter is Saturn, its distance from the sun 
being 872,000,000 miles, its periodic time 10,769 days, and 
its diameter 72,000 miles. 

Then comes Uranus, 1,753,000,000 miles from the sun, 
its periodic time 30,686 days, and its diameter 33,000 
miles. And last and most remote of the eight is Neptune, 
at the enormous distance of 2,746,000,000 miles from the 
sun, its periodic time being 60,126 days, and its diameter 
37,000 miles. And here, as far as we know, is the limit 
of our planetary system, though numerous comets sweep 
far beyond it. 

What a vast circle this last or outside planet must de- 
scribe in its circuit around the sun ! too far away to be seen 
except with the telescope, while yet its relations with the 
sun are such as to bring it through its course in a given 
time with wonderful precision. 

Some of these planets have moons. The earth has one ; 
Jupiter four ; Saturn eight ; Uranus, four ; and Neptune, 
one : all, except those of Uranus, going eastward around 
their respective planets. 

All these planets and their moons have an axial motion 
eastward in the direction of their orbital motion. How is 
this? Did they once belong to the body of the sun? 
Modern science has located the sun in space, and called it 
a fixed star. Undoubtedly it is ; and it is also supposed to 
to be a variable star. Its diameter is 852,000 miles. 
Now the distance to the moon being 238,000 miles, the 
sun's diameter would be nearly equal to four times the dis- 
tance of the moon from the earth. The photograph and 



THE CELESTIAL INDICATOR. 11 

spectroscope have recently been called to our aid, and we 
know many of the component parts of the sun, such as 
sodium, calcium, barium, magnesium, iron, chromium, nickel, 
zinc, strontium, cadmium, cobalt, and hydrogen. We know 
it to be on fire, and white with heat. We also know it 
has an axial motion, and this too is eastward. Were the 
planets thrown from the sun by its axial motion ? If so, 
and tins occurring from time to time, the sun all the time 
retaining nearly its axial position, and the planet going 
off from near the sun's equatorial region, it would tend to 
form them in a line along the zodiac. The nutation of the 
sun's pole around a small ellipse of 14° diameter about the 
pole of the Ecliptic, in a long period might tend to break 
the parallel of their orbits a little, which is the fact ; the 
tangential (or throwing-off) force, and the attractive power 
of the sun, would tend to give them an orbital motion ; 
they, as parts of the parent body, would retain their axial 
motion. All this they have ; and the inference is, that 
they once belonged to the body of the sun, and, when first 
thrown off, shone by their own light ; but now, being crust- 
ed over, are seen by the reflected light of the sun. 

The Indicator will show their position along the zodiac, 
and aid in the comprehension of this theory of their form- 
ation, called the " Nebulous Theory." 

And what shall we say of the countless millions of stars, 
of which number our sun is but one, all with their respec- 
tive solar-systems, and then all grouped again into star- 
systems, wheeling probably eastward around remote central 
points of their own groups, our system moving, perhaps, 
around Alcyone, (one of the Pleiades,) but in periodic times 
too great for our comprehension ? 

Then again, what if these groups are combined, and mov- 



12 THE CELESTIAL INDICATOR. 

ing around other points in the universe, and this is only 
the threshold of the Great Universe ! How vast, then, the 
creation, and how numberless the spirits may be in the 
spirit- world ! And who can tell what countless glories in 
this science will yet be unfolded to us, in the new life, for 
endless ages to come ? 

The motion of the earth around the sun, and the changes of 
the seasons. 

Tighten the shaft of the Indicator by turning the nut on 
the outside ; then revolve the thumb slide (a part of the 
sun marked with an arrow) to the left and bring the 
earth around to the vernal equinox. Remember that the 
equinoctial points are always where the Equator of the 
Heavens intersects the Ecliptic. 

Observe that, if the little ball, representing the earth, were 
lit up by a light from the large brass ball, representing the 
sun, the light would fall equally upon both hemispheres of 
the earth. In this position the earth is represented as be- 
ing at the first point in Aries, on the first meridian at the 
vernal equinox, and the time about the 21st of September. 
The days and nights are of equal length. It is here that 
the earth's path crosses the equinoctial or Equator of the 
Heavens 

We will now turn the slide and start the earth upward 
in its path along the Ecliptic, which now lies on the north- 
ern side of the Equator of the Heavens. It goes up (R. A.) 
eastward, a little inclining to the north pole of the Heavens, 
(N. D.) TTe pass through the latter part of September, 
October, November, and on to December 21st. The earth 
has now arrived at the winter solstice, 90° R. A., 23-| N. D., 
its greatest point of N. D., and has entered the sign of Can- 
cer, as seen in the zodiac. 



THE CELESTIAL INDICATOR. 13 

If the light came now from the brass ball, it would fall 
obliqnely upon the earth's northern and directly upon its 
southern hemisphere, this being caused by the earth's pass- 
ing up the northern part of the Ecliptic, at the same time 
keeping its axis parallel to the axis of the Heavens. It 
has departed, as you will see, 23^-° from the Equator, X. D., 
thus causing the sunlight to fall obliquely on our northern 
hemisphere, making our days short and cold ; while at the 
same time, the rays are direct on the southern hemisphere 
which makes its days long and warm. 

We pass the earth along about ten days more, and it 
arrives at its perihelion December 31st, and is at its nearest 
point to the sun, the earth's orbit being a little elliptical. 
We move it again. It now proceeds in R. A., and is 
approaching the equinoctial line, passing on through Janu- 
ary and February to the 21st of March, enters the sign 
of Libra at the Autumnal Equinox, R. A. 180°, and is 
again on the equinoctial line, declination 0°, having per- 
formed one-half of its journey around the sun. Again the 
days and nights are equal in length. Could we now look 
through the sun from the earth's position, our line of vision 
would carry us to our starting place ; consequently the 
sun appears at that point, and we say the sun has en- 
tered the vernal equinox. But during all this time it has 
been stationary ; remember that the appearance of the sun 
at this point is produced by our having traveled half around 
it. When the sun appears to us at this point in the 
Heavens, the year of the seasons commences. 

We now move the earth along, crossing the Equator of 
the Heavens or equinoctial line, to the south side of it. 
The earth begins to veer a little toward the south pole of 
the Heavens^ keeps along its path of R. A. through April, 



14 THE CELESTIAL INDICATOR. 

May, and to the 21st of June, entering the sign of Capri- 
cornus, when it is at the summer solstice, R. A. 270°, 
S. D. 231°. 

The longest and warmest days of the year have come, 
and on the Indicator you will see the sunlight falling di- 
rectly on the northern and obliquely on the southern 
hemisphere. 

In 17 days more of the earth's journey we arrive at its 
aphelion, July 8th, this being its greatest distance from 
the sun, 3,000,000 miles greater than at its perihelion, 
December 31st. 

The earth, having passed its greatest southern declina- 
tion, is again approaching the Equinoctial. We move it 
along through July and August to the 21st of September, 
and it again intersects the Equinoctial at the 1st degree in 
Aries, or the vernal equinox, the point from which it started, 
having made a journey of 360° R. A., and completed a 
tropical year, keeping its axis parallel to the axis of the 
Heavens all the way around. 

The earth 's axial motion. 

During this journey the earth revolves eastward on its 
axis 365^ times, as you see the little ball representing 
the earth on the Indicator move on its axis, when I turn 
it over eastward. Observe the small brass plane indicat- 
ing the horizon of its locality ; it is now opposite to the 
sun. As I turn it, it begins to come into the sunlight ; 
now it is sunrise. I move it a little more ; it is next to the 
sun, midday. Now again it is leaving the sunlight, or it is 
sundown ; now midnight. This is its daily axial motion. 

So it is in nature. The earth is a vast globe 8,000 miles 
in diameter, suspended in space and moving through it by 



THE CELESTIAL INDICATOR. 15 

the laws of motion and magnetism ; and travels l \vith un- 
varying regularity and precision annually around the sun 
exactly in the course pointed out by the Indicator. 

Thus you see why our seasons change, why we have 
w r arm and cold weather and the variation in the length of 
our days. 

I am now about to speak of phenomena which it is very 
important to fully comprehend ; and chiefly to aid in this, 
I have constructed the Celestial Indicator. 

The Precession of the Equinoxes (or the receding of the 
Equinoctial points on the Ecliptic) ; the ever changing 
position of the Equator of the Heavens, showing the de- 
clination of the stars as well as their right ascension, and 
the motion of the axis of the heavens around the pole of 
the Ecliptic. 

These phenomena are a unit ; movements so combined as 
to be inseparable from each other ; and so I have made them 
on the Indicator. They are caused by the earth being at- 
tracted by the sun and moon, the latter having far more influ- 
ence than the sun, and the greatest w T hen in that part of her 
orbit that diverges most from the earth's equator, having but 
little precessional effect in that part that leans toward the 
equator. While the sun exerts her influence most when the 
earth is at or near the solstices, both these influences act- 
ing together produce a displacement of the axis of the 
heavens, causing it to move w T estw r ard around the pole cf 
the Ecliptic. The Equator of the Heavens always keep- 
ing at right angles with its axis, of course it must move 
back on the Ecliptic, and the equinoxes, being the inter- 
secting points of the Equator and Ecliptic, must gradually 
lose their places on the Ecliptic, and be constantly but 
slowly falling back, or westward about one degree in seven- 
tv-one years. 



16 THE CELESTIAL INDICATOR. 

In the first place, let me describe that portion of the In- 
dicator which illustrates this subject. Notice that the shaft 
has several angles in it. We will commence at the north, 
pole of the Ecliptic, which is the end of the crooked shaft 
and pass up to the second angle of it. Here the line of 
the shaft rej)resentis the axis of the Heavens. This point 
is 23^° from the pole of the Ecliptic; consequently it is in- 
clined so much to its plane. Attached to this axis or 
shaft is a horizontal circle of wire, lying just within the first 
meridian, which it also represents. Crossing this wire at 
right angles to it, and just within the Equator of the 
Heavens, and representing it, is another circle of wire. 
These are made fast together and to the shaft. 

At the intersecting points of these two wires are the 
equinoctial points, the Vernal on the right, the Autumnal on 
the left. In revolving the shaft, I also revolve these two 
wires, which form a sphere (a sphere within the outer one, 
the frame-work). 

Remember that a sidereal year constitutes a complete 
revolution of the earth around the sun, from star around 
to the same star again. 

A tropical year, or year of the seasons, varies in no way 
from it, except that it is about twenty minutes shorter, 
inasmuch as it begins and ends at the equinoctial points, 
and these are in a backward motion constantly, thus clos- 
ing the year a little before the earth completes a revolution 
around the sun. 

The new year always commences on the instant the old 
one closes, the Equinox always being precisely where the 
new year begins. It then follows that the Equinox must 
lose its place among the stars and go back a little on the 
Ecliptic, to meet the short-year point, or back as far as the 



THE CELESTIAL INDICATOR. 17 

earth would travel in twenty minutes. Thus the stars are 
made to appear as advancing eastward in Iv. A., and this is 
called the precession of the Equinoxes, whose periodic 
time is about 25,000 years. 

2d. As the Equator of the Heavens must always inter- 
sect the Ecliptic at the Equinox, it follows that the Equator 
of the Heavens must change its position among the stars, 
and wind a little down on the Ecliptic to make the con- 
nection at the point where the year of the seasons ends. 
Consequently the declination of some of the stars is con- 
stantly changing, while others are gaining in polar distance. 
The amount of this variation is 47°. The periodic time is 
the same as that of the Equinoxes. 

Connected again with these movements is that of the 
axis of the Heavens, which always keeps its place, at right 
angles with the plane of its Equator. And as thy Equator 
winds down westward a little, marking the Equinox in a 
new place on the Ecliptic, so it must carry its axis along 
with it ; and this axis always being 23^-° from the pole of 
the Ecliptic, consequently in a long period it describes a 
circle of about 47° diameter around the pole of the Eclip- 
tic. This has been observed to be a fact for some thou- 
sands of years, and its periodic time is the same as that 
of the other great motions just described, viz., 25,000 years, 
or about 1° in 71 years. Here are some of the grand and 
combined movements of our solar-system. 

Now turn to the Indicator and revolve the shaft or axis 
of the Heavens, with the thumb piece on the outside, a 
little on its westward course around the pole of the Eclip- 
tic, and you will see the whole operation as described, and 
as it occurs in nature. 

Observe the position of Kegulus, 14° N. D. _ As you 



18 THE CELESTIAL INDICATOR. 

move the axis, the Equator winds around toward it, caus- 
ing it to lose its northern declination. While at the ver- 
nal equinox the stars gain in polar distance, at the same 
time you see the equinoctial points shift their places a lit- 
tle on the Ecliptic, and as they fall back give the appear- 
ance to all the stars as if they were moving eastward. 
Thus the constellations get in advance of their signs (the 
signs always keeping their places with the Equinoxes). 

Carry the axis of the Heavens a little further along, and 
El Rea becomes the pole-star, and as you proceed with it 
around the pole of the Ecliptic, it points to all the stars 
that have been or will be pole-stars for all past or future 
time. In about 6,000 years hence, Alderamin will be the 
pole-star, the vernal equinox will have reached the point 
on the Ecliptic of the present summer-solstice. The axis 
of the Heavens, and the line of the Equinoxes will then 
coincide with the plane of the Milky Way, and this vast 
zone of stars becomes a grand hour-circle of the Heavens. 

In about 11,500 years, the bright star Lyra will be the 
pole-star ; and so the axis of the Heavens moves along 
from star to star in its course around the pole of the Eclip- 
tic, coming again after the lapse of ages to « Draconis, 
which was the pole-star of the Egyptian, when he built 
the pyramids. 

The Indicator will point this out, and you will see that 
the axis has moved back about 60° westward since that 
time. A degree of this motion indicates about 71 years, 
which, multiplied by CO, makes over 4,000 years since the 
pyramids were built. That they were erected while « Dra- 
conis was the pole star is proved by their latitude and the 
angle of the passage-way into them. 

The vernal equinox then stood in the constellation of 
Gemini. 



THE CELESTIAL INDICATOR. 19 

Did those people know of this motion of the axis of the 
Heavens, or was it a still more remote people that placed 
the figure of Draco in the northern Heavens, its head near 
to Lyra, coiled around the pole of the Eel'} \ with its 
open month and forked tongue, emblematically figured and 
seeming to say forever to the unborn nations, " This is the 
pathway of the axis of the Heavens." 

The course of the Milky Way is represented on the In- 
dicator by a thin wire running around the sphere, crossing 
the Equator at about 96° R. A., and again at 274° R. A., 
to show its location. 

It is a great natural zone encircling the celestial sphere, 
composed of countless millions of stars " like glittering 
dust" on the dark vault of the Heavens, an unfathomable 
system of worlds, a unit and as a whole but an atom, com- 
pared to what is beyond in the great outlying nebulous 
regions, whieh embrace millions of like systems, that will 
yet be unfolded to us through great telescopes. 

The Moon. 
The moon is about 238,000 miles from the earth, and 
her diameter is 2,162 miles. She turns on her axis only as 
she moves around the earth. Her path is not precisely in 
the Ecliptic, but inclined to and crossing it, at an angle 
of a little over 5°, intersecting its plane at two opposite 
points, which are called the moon's nodes ; the ascending 
one being that passing from the southern to the north- 
ern side of the Equinoctial, the descending node thr t 
passing from the northern to the southern side. The nodes 
are constantly retreating or falling back on the Eclipt r c at 
the rate of about 19^° annually, performing a re olution 
"in a little less than nineteen years. Eclipses can never 



20 THE CELESTIAL INDICATOR. 

take place except when the moon is at or near one of her 
nodes. If she is within 17° of a node at the time of her 
change she will partially obscure the sun, and if within 12° 
of a node at the time of her full, she will pass into the 
earth's shadow and be partially eclipsed. These are called 
solar and lunar ecliptic-limits ; while if she is at one of her 
nodes, the eclipse, whether solar or lunar, is total. 

In a revolution of the moon around the sun, she com- 
pletes 12 lunations and begins on the thirteenth, and when 
she has been around times enough to have completed 223 
lunations, the sun, earth, and moon will return so nearly to 
the same relative positions, that in the next 223 lunations 
the same eclipses will occur again at the same times. This 
period was known to the Chaldeans, and by them was 
called the Saros. In it there are usually 41 eclipses of the 
sun, 29 of the moon, or 70 in all, so that, if we add 18 
years, 11 days, 40 minutes, 38 seconds to any eclipse of 
the sun or moon, we predict the same eclipse again at the 
end of that time. 

The ancients also knew another curious fact, that in ex- 
actly 19 tropical years there are exactly 235 new moons, 
and that at the end of this period they would repeat them- 
selves again at precisely the same times, during the following 
1 9 tropical years ; thus they could regulate their games and 
feasts, and this period was called the u Metonic Cycle." The 
places around the Ecliptic where eclipses occur vary as the 
nodes recede. Suppose an eclipse should occur when the 
node is in R. A. 30°, the next eclipse at the same node would 
be in R. A. 11°. You can illustrate this easily by the mova- 
ble nodes and revolving meridian on the Indicator. Notice 
the month and day when the eclipse occurs, and add 173 
days, and there will be an eclipse at the other node at the 



THE CELESTIAL INDICATOR. 21 

end of that period. Eclipses also occur in clusters at either 
node, in opposite seasons or months, which are called node- 
months. The semi-annual amount of the nodes' westward 
motion is marked on the disk that carries the nodes on the 
Indicator. The circle of wire on the Indicator, on which 
the moon's nodes are placed, represents the moon's path 
around the sun, showing the -5° 8' angle it has to the plane 
of the ecliptic. (This circle also answers to illustrate the 
manner in which all the planets cross the Ecliptic, at small 
but different angles, having their node-points on the Eclip- 
tic, but keeping within the limits of the zodiac.) 

The nodes are constantly in motion westward, and cause 
a continual variation of the moon's path among the stars, 
so that in one revolution of her nodes, the moon would oc- 
cult all the stars on the zodiac, that lie in the space of 
double the amount of the angle of her orbit's inclination, 
10° 16'. The Indicator gives a beautiful illustration of 
this, as may be seen by revolving the nodes. 

The moon, from conjunction ascending into the north- 
ern hemisphere of the heavens, until it is through half 
of its course, or fulled, begins to wane, goes down into the 
southern hemisphere to its conjunction again with the sun ; 
and, passing through its different phases, completes a luna- 
tion and one revolution on its axis. 

Place the moon in conjunction on the Indicator, and see 
the illustration. It now represents the old moon. Move it 
a little on its course. If it was now lit up by the ball rep- 
resenting the sun, the light would shine upon its lower 
half, and looking at it from the sundown point of the earth, 
you would see a little crescent of light on the lower limb 
precisely as you see it in nature. Passing the moon a lit- 
tle farther along on its eastward course (which is a little 



22 THE CELESTIAL INDICATOR. 

more than 12° per clay around the earth,) we bring it to its 
first quarter with its face to us half lit up ; we move it 
again and it is gibbous ; then it becomes full and is in op- 
position, (opposite to the sun.) It has now completed one- 
half of its course ; we move it along to its last quarter, 
passing into t^e southern hemisphere, and so along until it 
is near conjunction, when the little crescent of light would 
appear on the opposite side of where it was seen when it 
was new ; and instead of seeing this just after sundown, we 
see it just before sunrise. All this while, remember, the 
moon has been traveling along in its orbit through nearly one 
sign or almost 30°. Hence you see that the moon in going 
around the earth cannot return again to its starting point 
in the heavens, but can complete its course and easily ar- 
rive at its conjunction again with the sun. You will also 
observe that during this revolution it has made just one 
rotation on its axis. 

Nutation. 

Besides the general effect of the sun and moon in caus- 
ing the precession of the Equinoxes, is one due to the moon 
alone,' which is called nutation. The moon's nodes per- 
forming a revolution in about nhieteen years, during half 
of this time her orbit is inclined to the Ecliptic in the same 
way as the earth's equator ; during the other half of the 
time it diverges greatly from the earth's equator. In the 
former position its precessional effect is small, but in the 
latter posi-tion its effect is much greater, thus causing the 
north pole of the earth to describe westwarclly a small 
ellipse, exceedingly small, about the pole of the Heavens, 
during every period of nineteen years. To understand 
this backward motion, observe the right arm that supports 



THE CELESTIAL INDICATOR. 23 

the north pole of the earth on the Indicator in a revolution 
of the earth around the sun. You will see the arm attached 
to the cam move back westward, causing the north pole of 
the earth to move back with it, although the earth is on 
its eastward course around the sun, thus illustratino; the mo- 
tion of the earth's pole in relation to nutation. 

The Tides. 
The tides are the alternate rising and falling of the 
waters of the ocean. There are two high and two low 
tides each day, flood and ebb, day after day, year after 
year, and century after century. When it is flood-tide on 
one side of the earth, it is also flood-tide on its opposite side, 
and the same is true of ebb-tide. For an illustration, we 
will suppose the moon to be stationary, but all the while 
giving out her mysterious attraction, this influence exerting 
a lifting power on the waters of the earth, and also lifting 
the earth itself a little out of the waters under the earth, 
causing them to be ridged, or higher than they otherwise 
would be, so that the waters assume an ellipsoidal form, 
with the longer axis running through the highest point of 
the two high tides, and pointing to the moon. As the 
earth revolves on its axis fifteen degrees an hour, it would 
take one quarter, or 90° of its longitudinal surface, six 
hours, to pass by the direct influence of the moon. When 
the same section of 90° would be away from her influence, 
its middle point would be at low-tide. In six hours more 
this low-tide region will have revolved 90° further on to 
the high-tide point, or again into the line of the longest axis 
of the ellipsoid. The earth having now completed one-half 
of her revolution, and twelve hours gone by, in six hours 
more the same surface will be three-quarters round, and 



24 THE CELESTIAL INDICATOR. 

again out of the direct influence of the moon, and cnce 
more it is low-tide. Six hours more completes the day, 
and the same 90° of longitude occupies the place it started 
from, and, facing the moon, experiences high tide again. 

Now had the moon been in motion, (as she always is.) " 
she would have advanced a little in her orbit during this 
revolution of the earth, and consequently lengthened the 
time of the tides a little, inasmuch as the earth would have 
had to revolve about fifty minutes longer, in order to have 
placed the same surface under the moon's direct influence, 
thus making each tide of flood and ebb a few minutes over 
six hours in length. The tide remaining at its highest 
point but a few moments, then gradually subsides to its 
lowest point, then again rises, and so on forever. Thus 
the motion of the moon and the motions of the tides cor- 
respond. 

Spring and Neap Tide. 

We also have in each lunar month two high or spring 
tides, and two low or neap tides, caused by the increasing 
and diminishing of the above mentioned ellipsoidal form of 
the earth's waters. It must be remembered that the sun, 
though far away, has its attraction of the earth, and its 
tidal influence, though the latter small when compared 
to that of the moon. But when combined with the moon's 
attraction, it amounts to considerable, and tins always 
happens either at conjunction or when the moon is full, for 
then the major axis of the ellipsoidal form of the earth's 
waters is in a line through the earth and moon to the sun, 
and the moon, thus aided by the sun's influence, lifts the 
waters higher than the usual flood-tides, and these are 
called spring-tides. Xeap-ticles occur when the moon is in 



THE CELESTIAL INDICATOR. 25 

quadrature, or at its first and last quarters, when the tides 
are uncommonly low, for now the attracting influences of 
the moon and the sun are working against each other, pulling 
or lifting at right angles to each other, and the consequence 
is that the waters of the earth are made to assume a more 
spheroidal form. Then the tides are very low, and are 
called neap-tides. 

To illustrate, turn to the Indicator, and bring the earth 
for convenience to the winter-solstice ; place the moon at 
her full. The little brass plane on the earth we will use 
as a starting place. As it now stands facing the moon, it 
represents a high-tide ; opposite to this brass plane on the 
other side of the earth there would be a high-tide also. Now 
revolve the earth eastward and this point is leaving the face 
of the moon, in other words the tide is receding ; bring it 
quarter round and it will stand at a low-tide point ; contmue 
it onward and the tide is beginning to rise, and w T hen brought 
half round it will be at the high-tide place again, and the 
day is half finished. Move it round six hours more, and it is 
again at low-tide ; carry it along, and from this point of its 
revolution the tide begins to rise, and is at its height when 
it comes around to its starting point. Now suppose the 
moon has meanwhile advanced a little in its orbit ; you 
see that the duration of the tides will be increased some- 
what. 

Inferior and Superior Conjunctions. 

When either Venus or Mercury are between the earth 
and the sun, they are said to be in inferior conjunction, and 
when the sun is between either of them and the earth, they 
are said to be in superior conjunction. The superior planets 
are in conjunction, when the sun is directly between them 



26 THE CELESTIAL INDICATOR. 

and the earth, and in opposition, when the earth is between 
them and the sun. They never pass between the earth 
and the sun ; consequently they never have any inferior 
conjunction. This is illustrated on the Indicator, as the 
earth passes them in revolving around the sun. 

A transit across the disk of the sun of either Yenus or 
Mercury can happen only when the planet is at or very 
near one of her nodes, and in inferior conjunction. A 
transit may be illustrated in the same manner as a solar 
eclipse, by using for that purpose the ball which represents 
the moon. 

To understand the retrograde motion of a planet, observe 
one as you pass the earth around the sun ; you will see 
it in a certain sign of the zodiac. As the earth gets a little 
past it, observe again from the little ball representing the 
earth, and it will appear in another sign farther back on 
the zodiac. This gives the appearance of its having gone 
backwards, or in retrograde motion, though in nature the 
angle is much smaller. The planets can be placed in their 
respective signs, and then moved along from time to time, 
as they pass in their course around the sun. 

Children once knowing the planets' positions in the signs 
or constellations of the zodiac, and their periodic times, will 
always be enabled to point out their places in the Heav- 
ens, and will be much interested in so doing, and may be 
able very soon to apply the knowledge they derive from 
the Indicator to the actual heavens, thereby enlarging their 
minds and enabling themselves to comprehend something 
more than the mere elements of the science. 

In a synopsis of descriptive astronomy (and a short de- 
scription of the Celestial Indicator,) but little can be said 
on so grand a subject. It is hoped and confidently be- 



THE CELESTIAL INDICATOR. 27 

lieved that the Indicator will give a new impulse to the 
study by its capacity to elucidate, and that very much time 
can be saved, and the elements of the subject be better under- 
stood by its use. It was the intention of the inventor to 
compile a class-book to accompany the Indicator, but after 
looking over the numerous class-books on the elements 
of Astronomy and finding them so ably prepared, and so 
well adapted to illustrate the science, he abandoned the 
task. The writer would particularly recommend to teach- 
ers, the " Elements of Astronomy, by John Brocklesby, 
LL. D.," Professor of Mathematics and Natural Philoso- 
phy, in Trinity College, Hartford. 

H. B. 
Hartford, Dec. 15th, 1870. 



The apparatus is made of brass ; is simple, durable, 
and elegant in construction ; not liable to get out of or- 
der, occupies about a cubic foot, and will be carefully 
boxed and directed to any part of the country. 

PRICE $25.00. 



TESTIMONIALS 



Among the many favorable opinions received, the fol- 
lowing, from well-known gentlemen and teachers, are 
presented to the public : 

The Celestial Indicator, invented ana* constructed by Mr. Henry 
Bryant, is a simple apparatus which illustrates with great clearness 
many important astronomical phenomena. 

It is a celestial sphere within which the sun and planets are 
placed in their proper positions. All the parts have freedom of 
motion whenever motion is required for the elucidation of a truth. 
Without entering into detail, a few of the most striking illustrations 
are the following : 

The subject of celestial measurements is made very clear, the 
meaning of right ascension and declination being seen at a glance. 

The precession of the equinoxes is beautifully shown, also the 
changes consequent thereon of the places of the fixed stars, referred 
to the vernal equinox, the ecliptic, and celestial equator, and the 
varying positions of the poles of the heavens through thousands of 
years. The changes of the seasons, the phases of the moon, and 
eclipses, both solar and lunar, are all illustrated. 

The conjunction, oppositions, and the direct and retrograde 
motions of the planets are also explained by means of this apparatus, 
and likewise the transits of Mercury and Venus. 

From an examination of the Celestial Indicator, I am of 
opinion that it well deserves a place in our schools where the 
elements of astronomy are taught, and I know of no other similar 
apparatus now in use that contains such an amount of accurate 
illustration at so small a price. 

JOHN BROCKLESBY, 

Professor of Mathematics and Natural Philosophy 

in Trinity College. 
Hartford, Oct. 21, 1870. 



I have examined a Celestial Sphere recently invented by Mr. 
Henry Bryant, and desire to recommend it unhesitatingly to the 
attention of all interested in astronomy, particularly teachers. The 
last five years have been prolific in new and beautiful mechanical 
contrivances for illustrating the movements of the heavenly bodies. 
Nevertheless, Mr. Bryant's apparatus being quite unique and dif- 
ferent from all others, deserves a place in every good collection of 
scientific apparatus on its own peculiar merits. By an ingenious 
contrivance, the inventor has so arranged miniature axes of the 
equator and ecliptic, that the one may be made to revolve 
about the other, illustrating with beautiful simplicity and clearness 
those problems of astronomy which it is usually extremely difficult 
for teachers to explain or scholars to comprehend. I refer to the 
precession of the equinoxes, and the various phenomena depending 
upon it, such as nutation, the change of the pole star, changes in the 
declination and right ascension of stars, the difference between the 
sidereal and tropical years, the retrogradation of the signs of the 
Zodiac, etc. If the instrument did nothing more than this, I should 
deem it invaluable for instruction in astronomy, as illustrating the 
very points which most need illustration. But I must add that 
other astronomical phenomena are explained by this apparatus, 
with sufficient clearness, particularly the revolution of the moon's 
nodes, the whole subject of lunar and solar eclipses, the lunar 
occulation of stars, the inclination of the planetary orbits to the 
ecliptic, the direction of the sun's axis of rotation, etc. 

This apparatus does not, in my judgment, entirely supersede the 
necessity of a good celestial globe, but it forms an admirable 
supplement to the latter, and may be used with great profit wherever 
astronomy is studied. 

S. M. CAPRON, 

Principal of the H. P. H. S. 
Hartford, Oct. 6, 1871. 



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